Settings > Apps > Telegram > Storage > Clear Cache.
A single string of text can completely crash your Telegram application. Known in cybersecurity circles as a "crush bug" or "crash code," this phenomenon exploits how software processes specific characters. When a user receives or opens a message containing these rogue characters, the app freezes, shuts down, or enters a continuous crash loop. crush bug telegram
If by "covering," you mean hiding text so it doesn't spoil a message, Telegram uses a feature. Settings > Apps > Telegram > Storage > Clear Cache